JP2002005046A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scroll compressor capable of preventing fluid leakage. SOLUTION: A back pressure chamber HR is formed at the other end of an end plate 12(a) of a fixed scroll 12, the fixed scroll 12 is pressed to a revolving scroll 13 by introducing compression fluid into the back pressure chamber HR. Steps are installed at end plates 12(a) and 13(a) of the fixed scroll 12 and the revolving scroll 13, and wall bodies 12b and 13b of upper margins of the fixed scroll 12 and the revolving scroll 13 are shaped with steps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor provided in an air conditioner, a refrigeration system, and the like.

[0002]

2. Description of the Related Art In a scroll compressor, a fixed scroll and an orbiting scroll are arranged by combining spiral-shaped walls with each other, and the orbiting scroll revolves orbitally with respect to the fixed scroll to form a compression formed between the walls. The fluid in the compression chamber is compressed by gradually reducing the volume of the chamber.

[0003] The design compression ratio of a scroll compressor is such that the maximum volume of the compression chamber (the wall is engaged with the minimum volume of the compression chamber (the volume immediately before the compression chamber disappears due to the disengagement of the walls). (The volume at the time when the compression chamber is formed), and is expressed by the following formula (I). Vi = {A (θsuc) · L} / {A (θtop) · L} = A (θsuc) / A (θtop) (I) In the equation (I), A (θ) is the turning angle θ of the orbiting scroll. A function representing the cross-sectional area parallel to the revolving surface of the compression chamber, the volume of which varies according to the following equation: θsuc is the revolving angle of the revolving scroll when the compression chamber has the maximum volume, and θtop is the revolving angle when the compression chamber has the minimum volume. The turning angle L of the scroll is the wrap (overlap) length between the wall bodies.

Conventionally, in order to improve the compression ratio Vi of a scroll compressor, a technique has been adopted in which the number of turns of the wall bodies of both scrolls is increased to increase the cross-sectional area A (θ) of the compression chamber at the maximum capacity. Have been. However, the conventional method of increasing the number of windings on the wall enlarges the outer shape of the scroll and increases the size of the compressor itself, so that it is difficult to adopt the method in an air conditioner for an automobile or the like whose size is severely restricted. was there.

In order to solve the above problems, Japanese Patent Publication No. Sho 60-179
No. 56 proposes the following technology. FIG.
(a) shows the fixed scroll 50 and the end plate 5.
0a, and a spiral wall 50b erected on one side surface of the end plate 50a. Also, the one shown in (b) is the orbiting scroll 51. Like the fixed scroll 50, the orbiting scroll 51 also includes an end plate 51a, and a spiral wall 51b provided upright on one side surface of the end plate 51a.

The side walls of the fixed scroll 50 and the end plates 50a, 51a of the orbiting scroll 51 have wall bodies 50b, 51a.
Steps 52, 52 are formed at π (rad) from the outer end of the spiral of b, and are higher at the center and lower at the outer end. Further, the step portions 52, 5 of the end plates 50a, 51a
Walls 5 provided for both scrolls 50 and 51 corresponding to 2
Stepped portions 53, 53 having a lower center portion and a higher outer terminal side are formed at the spiral upper edges of 0b and 51b. Tip seals 54 and 56 for improving airtightness are provided on the upper edges of the walls 50b and 51b.

In the above-described scroll compressor,
The fixed scroll 50 and the orbiting scroll 51 are engaged with the respective walls 50b, 51b to form the compression chamber P having the maximum volume.
FIG. 13 (a) shows a state in which is formed, and FIG. 13 (b) is a cross-sectional view of the compression chamber P along the spiral direction. Figure 1
As can be seen from FIG. 3 (b), the wrap length L1 on the outer end side of the step 52 is formed longer than the inner wrap length Ls. For this reason, it can be seen that the maximum volume of the compression chamber P is increased by the length of the wrap outside the step portion 52 as compared with the case where the wrap length is uniform. Therefore, it is possible to improve the designed compression ratio without increasing the number of turns of the wall.

[0008]

However, in the above-described conventional scroll compressor, as shown in FIG.
The tip seal 56 near the end plate 5 of the fixed scroll 50
0a (part indicated by reference numeral a in the figure).
Similarly, the tip seal 54 of the orbiting scroll 51 is provided near the step 52 in the tip seal 54 on the fixed scroll 50 side.
1a. Therefore, the tip seal 5
4 and 56 fall from the walls 50b and 51b, respectively, and breakage of the chip seals 54 and 56 is caused.

The present invention has been made in view of the above circumstances, and has as its object to provide a scroll compressor capable of preventing leakage of a fluid.

[0010]

According to a first aspect of the present invention, there is provided a scroll compressor comprising a fixed scroll having a spiral wall provided on one side surface of an end plate, and a fixed scroll provided on one side surface of the end plate. A scroll scroll having a spiral-shaped wall body, and a revolving scroll supported to be capable of revolving orbiting while being prevented from rotating by meshing with each other,
A back pressure chamber is formed on the other side surface of the end plate of at least one of the fixed scroll and the orbiting scroll, and the fluid compressed by the two scrolls is introduced into the back pressure chamber to form one of the scrolls. The scroll is configured to be pressed against the other scroll side.
An end plate of at least one of the fixed scroll and the orbiting scroll is formed on the one side surface so that its height is higher at the center portion side and lower at the outer terminal side along the vortex of the wall. The upper edge of the wall of the other scroll of the fixed scroll and the orbiting scroll corresponds to the step of the end plate, is divided into a plurality of portions, and the height of the portion is The vortex has a stepped shape that is lower on the center side and higher on the outer end side.

In this scroll compressor, one scroll is pressed against the other scroll by the compressed fluid introduced into the back pressure chamber. Therefore, the compression chamber is sealed without using a tip seal as in the related art, and leakage of the fluid in the compression chamber can be prevented. Therefore, problems such as dropping and breakage of the chip seal caused by separation of the chip seal from the end plate do not occur.

A scroll compressor according to a second aspect of the present invention is the scroll compressor according to the first aspect, further comprising an elastic body that presses at least one of the fixed scroll and the orbiting scroll against the other scroll. It is characterized by being.

In this scroll compressor, one scroll is pressed against the other scroll by the elastic body, so that leakage of fluid is prevented.

According to a third aspect of the present invention, in the scroll compressor according to the first or second aspect, the back pressure chamber is formed on the other side of the fixed scroll. I do.

In this scroll compressor, the compression chamber is sealed by pressing the fixed scroll toward the orbiting scroll.

According to a fourth aspect of the present invention, in the scroll compressor according to the first or second aspect, the back pressure chamber is formed on the other side of the orbiting scroll. I do.

In this scroll compressor, the compression chamber is sealed by pressing the orbiting scroll toward the fixed scroll.

A scroll compressor according to a fifth aspect of the present invention is the scroll compressor according to the fourth aspect, further comprising a bearing member that revolves around the end face of the orbiting scroll by revolving orbiting. The back pressure chamber is formed between the orbiting scroll and the bearing member.

In this scroll compressor, the compressed fluid introduced into the back pressure chamber exerts a pressure to push and spread between the orbiting scroll and the bearing member. Thereby, the orbiting scroll is pressed against the fixed scroll.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a scroll compressor according to the present invention will be described with reference to FIGS. FIG.
1 shows a configuration of a back-pressure scroll compressor shown as one embodiment of the present invention. In the drawing, reference numeral 1 denotes a sealed housing, and 2 denotes a high-pressure chamber HR and a low-pressure chamber L in the housing 1.
Discharge cover separated into R, 5 is frame,
Reference numeral 6 denotes a suction pipe, 7 denotes a discharge pipe, 8 denotes a motor, 9 denotes a rotating shaft, and 10 denotes a rotation preventing mechanism.

Reference numeral 12 denotes a fixed scroll, 13
Is a revolving scroll that meshes with the fixed scroll 12. As shown in FIG. 2, the fixed scroll 12 includes an end plate 12.
A spiral wall 12b is provided upright on one side surface of a. The orbiting scroll 13 is a fixed scroll 1
2, a spiral wall 13b is provided on one side surface of the end plate 13a.
The wall 13b has substantially the same shape as the wall 12b on the fixed scroll 12 side. The orbiting scroll 13 is assembled such that the walls 12b and 13b are engaged with each other in a state where the orbiting scroll 13 is eccentric with respect to the fixed scroll 12 by an orbital orbital radius and shifted in phase by 180 °. In such a back-pressure scroll type fluid machine, the fixed scroll 12 is not completely fixed to the frame 5 by bolts or the like, and is movable within a restricted range.

A cylindrical boss A is formed on the back side of the orbiting scroll 13, and an eccentric pin 9a provided at the upper end of a rotary shaft 9 driven by the motor 4 and orbiting is inserted into the boss A. I have. As a result, the orbiting scroll 13 orbits with respect to the fixed scroll 12, and its rotation is prevented by the operation of the rotation preventing mechanism 10. On the other hand, the fixed scroll 12 is
Spring (elastic body) 1 for frame 5 fixed to
1 and supported against the orbiting scroll 13 side. A discharge port 15 for compressed fluid is provided at the center of the back surface of the end plate 3a. A cylindrical flange 16 protruding from the back of the end plate 12a of the fixed scroll 12 is provided around the discharge port 15.
The cylindrical flange 16 is fitted to the cylindrical flange 17 on the discharge cover 2 side. A high-pressure chamber HR is provided in a portion where these cylindrical flanges 16 and 17 are fitted.
And the low pressure chamber LR, it is necessary to apply a high pressure (back pressure) to the back of the fixed scroll 12 to push it down.
A seal structure using a seal member 18 is employed. The seal member 15 has a U-shaped cross section.
In this case, the high-pressure chamber HR also functions as a back-pressure chamber that applies a high-pressure discharge pressure to the back of the fixed scroll 12.

An end plate 12a of the fixed scroll 12 is provided with a step formed on one side of the wall 12b on which the wall 12b is erected so as to be higher at the center and lower at the outer end along the vortex direction of the wall 12b. A portion 42 is provided. Similarly to the end plate 12a, the end plate 13a on the side of the orbiting scroll 13 is formed on one side surface on which the wall 13b is erected so as to be higher at the center and lower at the outer end along the vortex direction of the wall 13b. The stepped portion 43 is provided. Each of the step portions 42 and 43 includes a wall 12b,
With reference to the center of the spiral of the wall 13b, each wall 12b, 1
It is provided at a position advanced by π (rad) from the outer end of 3b.

The bottom surface of the end plate 12a is formed with a stepped portion 42 so that a shallow bottom surface 12f provided near the center and a deep bottom surface 12f provided near the outer end.
g is divided into two parts. Adjacent bottom surface 12
f, 12g, a step portion 42 is formed, and the bottom surface 12
There is a connecting wall surface 12h that connects f and 12g and stands vertically. The bottom surface of the end plate 13a is also similar to the end plate 12a,
Due to the formation of the stepped portion 43, it is divided into two portions, a shallow bottom surface 13f provided at the center and a deep bottom surface 13g provided at the outer end.
Between the adjacent bottom surfaces 13f and 13g, there is a connecting wall 13h which forms a step 43 and connects the bottom surfaces 13f and 13g to be vertically cut.

A wall 12b on the fixed scroll 12 side is provided.
Corresponds to the step portion 43 of the orbiting scroll 13, and has a spiral upper edge that is divided into two portions, and has a stepped shape that is lower at the center of the spiral and higher at the outer end side. The wall 13b on the orbiting scroll 13 side is similar to the wall 12b,
Corresponding to the step portion 42 of the fixed scroll 12, the spiral upper edge is divided into two portions, and has a stepped shape that is lower at the center of the spiral and higher at the outer end side.

Specifically, the upper edge of the wall 12b is divided into two parts, a lower upper edge 12c provided near the center and a higher upper edge 12d provided near the outer end. Between the matching upper edges 12c and 12d, there is a connecting edge 12e that connects the two and is perpendicular to the turning surface. Similarly to the wall body 12b, the upper edge of the wall body 13b is a lower upper edge 13c provided near the center and a higher upper edge 13d provided near the outer end.
Divided into two parts, and adjacent upper edges 13c, 13d
Between them, there is a connecting edge 13e that connects the two and is perpendicular to the turning surface.

When the wall 12b is viewed from the direction of the orbiting scroll 13, the connecting edge 12e has a semicircle having a diameter which is smoothly continuous with the inner and outer side surfaces of the wall 12b and has a diameter equal to the wall thickness of the wall 12b. Similarly to the connection edge 12e, the connection edge 13e smoothly continues to both inner and outer side surfaces of the wall 13b.
It forms a semicircle having a diameter equal to the thickness of b.

When the end plate 12a is viewed from the direction of the revolving axis, the connecting wall surface 12h forms an arc which coincides with the envelope drawn by the connecting edge 13e as the revolving scroll is turned. The connecting wall surface 13h is also connected to the connecting wall surface 12h. Similarly, the connecting edge 12e
It forms an arc that matches the envelope drawn by. Note that a tip seal is not provided on the upper edge of the wall 12b of the fixed scroll 12 and the wall 13b of the orbiting scroll 13 in this example, and the end faces of the walls 12b, 13b are connected to the end plates 12a, 1b.
The compression chamber C, which will be described later, is sealed by being pressed by 3a.

As shown in FIG. 4, a rib 12i is provided on the wall 12b at the portion where the upper edge 12c and the connecting edge 12e abut against each other. Rib 12i
Is formed integrally with the wall body 12b to form a concave curved surface that smoothly connects the upper edge 12c and the connection edge 12e in order to avoid stress concentration. Upper edges 13c, 13 in the wall 13b
The rib 13 of the same shape is also provided at a portion where
i is provided.

In the end plate 12a, where the bottom surface 12g and the connecting wall surface 12h meet each other, the rib 1
2j are provided. The rib 12j is formed integrally with the wall 12b to form a concave curved surface that smoothly connects the bottom surface 12g and the connecting wall surface 12h in order to avoid stress concentration.
A rib 13j having the same shape is provided also at a portion where the bottom surface 13g and the connecting wall surface 13h abut on the end plate 13a for the same reason.

The upper edge 12d and the connecting edge 1 of the wall 12b
2e, and the upper edge 1 of the wall 13b.
The portions where the 3d and the connecting edge 13e abut are chamfered to avoid interference with the ribs 13j and 12j during assembly.

The fixed scroll 12 and the orbiting scroll 13
Is assembled, the lower upper edge 13c becomes the shallow bottom 12
f, and the upper edge 13d of the higher position contacts the deep bottom surface 12g. At the same time, the lower upper edge 12c is
3f, the upper edge 12d of which is higher than that of the lower bottom 13g
Abut. As a result, the compression chamber C is defined between the scrolls by the end plates 12a and 13a and the wall bodies 12b and 13b facing each other.

The compression chamber C moves from the outer end toward the center with the revolving orbiting motion of the orbiting scroll 13, but the connecting edge 12e is connected to the contact edge of the wall 12b.
e, it is in sliding contact with the connecting wall surface 13h so as not to leak fluid between the adjacent compression chambers C (one is not in a closed state) with the wall member 12 interposed therebetween, while the wall member 12 is located closer to the outer end.
As long as the contact points of b and 13b are not closer to the outer end than the connection edge 12e, the connection wall surface 13h for equalizing pressure between the adjacent compression chambers C (both in a closed state) with the wall body 12 interposed therebetween.
Is not slid on.

Similarly, the connecting edges 13e are also provided on the walls 12b, 13b.
As long as the contact point b is located closer to the outer end than the connection edge 13e, the connection wall surface 1 is arranged so that fluid does not leak between the adjacent compression chambers C (one of which is not in a sealed state) with the wall 13 interposed therebetween.
2h, and the contact points of the wall bodies 12b and 13b are
As long as it is not closer to the outer end than 3e, it does not slide on the connecting wall 12h in order to equalize the pressure between the adjacent compression chambers C (both in a closed state) with the wall 13 interposed therebetween. The sliding contact between the connecting edge 12e and the connecting wall surface 13h and between the connecting edge 13e and the connecting wall surface 12h are made by the orbiting scroll 1
It occurs synchronously while 3 rotates ３.

The process of fluid compression at the time of driving the scroll compressor configured as described above will be described in order with reference to FIGS. In the state shown in FIG. 5, the outer end of the wall 12b contacts the outer surface of the wall 13b, and the outer end of the wall 13b contacts the outer surface of the wall 12b.
Fluid is sealed between the walls 2a and 13a and the walls 12b and 13b, and two compression chambers C each having a maximum capacity are formed at a position facing the center of the scroll compression mechanism. At this time, the connecting edge 12e and the connecting wall surface 13h are in sliding contact with each other, and the connecting edge 13e and the connecting wall surface 12h are in sliding contact with each other, but are separated immediately thereafter.

From the state shown in FIG.
In the process of turning by two and reaching the state shown in FIG.
Advances toward the center while maintaining the sealed state, gradually reduces the volume and compresses the fluid, and the compression chamber C0 preceding the compression chamber C also advances toward the center while maintaining the sealed state,
The fluid is then compressed by progressively reducing the volume. In this process, the connection edge 12e, the connection wall surface 13h, and the connection edge 1
Sliding contact between 3e and the connecting wall surface 12h is canceled, and two adjacent compression chambers C are equalized.

From the state shown in FIG.
In the process of turning by two and reaching the state shown in FIG.
Progresses toward the center while maintaining the sealed state, gradually reduces the volume and further compresses the fluid, and the compression chamber C0 also advances toward the center while maintaining the sealed state, gradually reduces the volume and continues Compress the fluid. In this process, the connecting edge 12e starts sliding contact with the connecting wall surface 13h, and the connecting edge 13e starts sliding contact with the connecting wall surface 12h.

In the state shown in FIG. 7, the wall 1 near the outer end
An open space C1 that later becomes a compression chamber is formed between the inner surface of the inner wall 2b and the outer surface of the wall 13b located inside the inner wall 2b.
Similarly, an open space C1 which is to be a compression chamber later is formed between the inner surface of the wall 13b near the outer end and the outer surface of the wall 12b located inward thereof, and the open space C1 has a low-pressure chamber LR.
, A low-pressure fluid flows in.

From the state shown in FIG.
In the process of turning by two and reaching the state shown in FIG. 8, the open space C1 advances toward the center of the scroll compression mechanism while expanding in size, and the compression chamber C preceding the open space C1 also moves toward the center. To compress the fluid by gradually reducing its volume.

In the process in which the orbiting scroll 13 further turns by π / 2 from the state shown in FIG. 8 to the state shown in FIG. 5 again, the space C1 further advances toward the center of the scroll compression mechanism while expanding its size. Then, the compression chamber C preceding the space C1 also advances toward the center while maintaining a sealed state, and gradually reduces the volume to compress the fluid. When the state shown in FIG. 5 is reached, the compression chamber C shown in FIG. 8 corresponds to the compression chamber C0 shown in FIG. 5, and the space C1 shown in FIG. 8 corresponds to the compression chamber C shown in FIG. Thereafter, by continuing the compression, the compression chamber C becomes the minimum volume, and the fluid is discharged from the compression chamber C.

The discharged fluid is introduced into the high-pressure chamber HR. Then, the fixed scroll 12 receives a high back pressure and is pressed against the orbiting scroll 13. In the sealing member 15, the high pressure fluid is introduced into the U-shaped portion to expand the width by the differential pressure, and the sealing member 15 is sealed. When the surfaces are pressed toward the vertical surfaces of the cylindrical flanges 16 and 17, the high-pressure chamber HR and the low-pressure chamber LR are sealed.

Next, the change in the shape of the compression chamber C will be described. The change in the size of the compression chamber C from the maximum volume to the minimum volume is as follows: the compression chamber C in FIG. 5 → the compression chamber C in FIG.
The compression chamber C0 in FIG. 5 can be regarded as the compression chamber C0 in FIG. Here, the expanded shape of the compression chamber in each state is shown in FIG.

In the state (a) where the maximum volume is reached, the compression chamber has a strip shape of an irregular shape in which the width in the direction of the swivel axis is reduced halfway. The width thereof is the height of the wall 12b from the bottom surface 12g to the upper edge 12d (or the height of the wall 13b from the bottom surface 13g to the upper edge 13d) on the outer end side of the scroll compression mechanism.
And the wrap length Ll is approximately equal to
The wrap length Ls (<Ll) is substantially equal to the height from 2f to the upper edge 12d (or the height of the wall 13b from the bottom surface 13f to the upper edge 13d).

Also in the state (b), the compression chamber has an irregular strip shape whose width in the direction of the swivel axis is reduced halfway. The width is the wrap length Ls on the outer end side of the scroll compression mechanism, and the height from the bottom surface 12f to the upper edge 12c (or the wall 13 from the bottom surface 13f to the upper edge 13c) on the center side.
wrap length Ls (<Ls).

As the compression further proceeds, the width of the compression chamber has a uniform wrap length Lss as shown in FIG. Then, as shown in (d), the length is minimized,
The compression chamber has a minimum volume.

In the scroll compressor described above, the change in the volume of the compression chamber is caused not only by the decrease in the cross-sectional area parallel to the turning surface as in the conventional case, but also by the width in the turning axis direction as shown in FIG. Is caused synergistically by the reduction of the cross-sectional area.

Therefore, the wall bodies 12b and 13b are stepped, and the wrap length of the wall bodies 12b and 13b is changed between the outer end and the center of the scroll compression mechanism to increase the maximum volume of the compression chamber C. By reducing the minimum volume or the minimum volume, the compression ratio can be improved as compared with the conventional scroll compressor in which the wrap length between the walls is constant. Then, the fixed scroll 12 is pressed against the orbiting scroll 13 by introducing the back pressure into the high-pressure chamber HR.
For this reason, the compression chamber C is sealed without using the tip seal, so that efficient compression can be performed without dropping or breaking the tip seal.

Next, a second embodiment of the present invention will be described. In addition, about the structure same as the said 1st Embodiment, the description is abbreviate | omitted using the same code | symbol. FIG.
1 shows a scroll compressor according to the present embodiment.
In the figure, reference numeral 21 denotes a sealed housing having a suction pipe 23 at a lower part and a discharge pipe 25 at an upper part. Inside the housing 21, a drive unit 27 is provided at the upper part, and a compressor part 29 is provided at the lower part.
Are provided respectively. The drive unit 27 includes a rotor 27a fixed to the main shaft 28 and a stator 27b fixed to the housing 21. The main shaft 28 is rotatably supported by a main bearing 30.
When a current flows through b, rotational power is applied to the main shaft 28 via the rotor 27a.

The compressor section 29 comprises a fixed scroll 31 and an orbiting scroll 32. Fixed scroll 31
Is fixed to the housing 21. A discharge port 33 for compressed fluid is provided at the center of the end plate of the orbiting scroll 32 (note that unlike the first embodiment, the fixed scroll 31 has a discharge port (reference numeral in FIG. 1). 15) is not provided). On the back side of the orbiting scroll 32, a cylindrical boss A is formed surrounding the opening of the discharge port 33, and the boss A is
Eccentric portion 28a is inserted. Fixed scroll 31
The other configuration of the orbiting scroll 32 is the same as that of the fixed scroll 12 and the orbiting scroll 13 in the first embodiment. Steps 42 and 43 are formed on the end plates, and the stepped wall 12b is formed. , 13b.

A communication hole 34 is provided in the main shaft 28 so as to penetrate in the axial direction, and connects the discharge port 33 and the discharge pipe 25. Further, between the orbiting scroll 32 and the main bearing 30, a high-pressure chamber (back pressure chamber) is formed in the housing 21.
An annular seal member 35 for separating and sealing the HR and the low-pressure chamber LR is provided. The high-pressure chamber HR is formed around the opening of the discharge port 33 on the back side of the orbiting scroll 32.

In this scroll compressor, when the orbiting scroll 32 is revolved orbiting, the compression chamber C moves from the outer end toward the center, and gradually reduces the volume to compress the fluid. The compression stroke of the fluid is the same as that of the first embodiment, but the compressed fluid
Through the high-pressure chamber HR formed on the back side of the orbiting scroll 32. Then, the orbiting scroll 32 receives a high back pressure and is pressed against the fixed scroll 31.

In the scroll compressor of the present embodiment, the change in the volume of the compression chamber is caused not only by the decrease in the cross-sectional area parallel to the turning surface as in the conventional case, but also in the direction of the turning axis as shown in FIG. Is caused synergistically by a decrease in the width of the cross section and a decrease in the cross sectional area.

Therefore, the wall bodies 12b and 13b are stepped, and the wrap length of the wall bodies 12b and 13b is changed between the outer end and the center of the scroll compression mechanism to increase the maximum volume of the compression chamber C. By reducing the minimum volume or the minimum volume, the compression ratio can be improved as compared with the conventional scroll compressor in which the wrap length between the walls is constant. Then, the orbiting scroll 32 is pressed against the fixed scroll 31 by introducing the back pressure into the high-pressure chamber HR.
For this reason, the compression chamber C is sealed without using the tip seal, so that efficient compression can be performed without dropping or breaking the tip seal.

Next, a third embodiment of the present invention will be described. In addition, about the structure same as the said 1st Embodiment, the description is abbreviate | omitted using the same code | symbol. FIG.
In the figure, reference numeral 13 ′ denotes an orbiting scroll meshed with the fixed scroll 12. Orbiting scroll 13 '
Is composed of an end plate 13a 'and a wall 13b provided upright on one side surface of the end plate 13a'. Except for the end plate 13a ', the configuration is the same as that of the orbiting scroll 13 of the first embodiment. On the end plate 13a 'of the orbiting scroll 13', an annular groove 45 is formed on the back side (the other side surface of the end plate 13a '). A bearing member 46 is fitted in the annular groove 45. An annular projection 46 a corresponding to the annular groove 45 is formed on the bearing member 46, and the annular projection 46 a is fitted into the annular groove 45. Annular projection 46a
A seal member 47 is provided on the seal surface between the orbital groove 45 and the gap between the orbiting scroll 13 ′ and the bearing member 46 so that the gap between the orbiting scroll 13 ′ and the central side high pressure chamber (back pressure chamber) HR ′ It is separated from the outside low pressure chamber LR. The end plate 13a 'is provided with a communication hole 48 for communicating the high-pressure chamber HR' with the compression chamber C.

The bearing member 46 is formed with a cylindrical boss A extending on the opposite side to the annular projection 46a, and the eccentric pin 9a provided at the upper end of the rotary shaft 9 and revolving is inserted into the boss A. Further, the bearing member 46 is supported in a state where its rotation is prevented by the rotation preventing mechanism 10. As a result, the bearing member 46 is revolved orbitally by the rotation of the rotating shaft 9, and the motion is transmitted to the orbiting scroll 13 ′ and the orbiting scroll 13 ′.
Is designed to revolve.

In this scroll compressor, when the orbiting scroll 13 'revolves orbitally, the compression chamber C moves from the outer end toward the center, and gradually reduces the volume to compress the fluid. The compression stroke of the fluid is the same as that of the first embodiment, but the compressed fluid is supplied to the discharge port 15.
From the high-pressure chamber H through the communication hole 48.
R ′. The high-pressure fluid introduced into the high-pressure chamber HR ′ exerts pressure so as to separate the orbiting scroll 13 ′ and the bearing member 46 from each other, whereby the orbiting scroll 13 ′ is pressed against the fixed scroll 12.

In the scroll compressor of this embodiment, the change in the volume of the compression chamber is not caused only by the decrease in the cross-sectional area parallel to the orbital surface as in the conventional case, but is changed in the direction of the orbital axis as shown in FIG. Is caused synergistically by a decrease in the width of the cross section and a decrease in the cross sectional area.

Therefore, the wall bodies 12b and 13b are formed in a stepped shape, and the wrap length of the wall bodies 12b and 13b is changed between the outer end and the center of the scroll compression mechanism to increase the maximum volume of the compression chamber C. By reducing the minimum volume or the minimum volume, the compression ratio can be improved as compared with the conventional scroll compressor in which the wrap length between the walls is constant. Then, by introducing the back pressure into the high pressure chamber HR ',
The fixed scroll 12 and the orbiting scroll 13 'are pressed against each other. For this reason, the compression chamber C is sealed without using the tip seal, so that efficient compression can be performed without dropping or breaking the tip seal.

In the above embodiment, the connecting edge 12
e and 13e are formed perpendicular to the revolving surface of the revolving scroll 13, and the connecting wall surfaces 12h and 13h are also formed perpendicular to the revolving surface correspondingly, but the connecting edges 12e and 13e and the connecting wall surfaces 12h and 13h are It is not necessary to be perpendicular to the turning surface as long as the mutual correspondence is maintained. For example, it may be formed so as to be inclined with respect to the turning surface. In addition, the connection edge 12
e and 13e need not be semicircular, but may be any shape. In this case, the connection edges 12e, 13e
Since the envelope drawn by is not an arc, the connecting wall 12
h and 13h are no longer arcs. Further, the formation portions of the step portions 42 and 43 are not limited to one position, and may be provided at a plurality of positions.

[0060]

As described above, in the scroll compressor of the present invention, one scroll is pressed against the other scroll by the compressed fluid introduced into the back pressure chamber. For this reason, since the compression chamber is sealed without using the conventional tip seal, it is possible to prevent the fluid from leaking and perform the compression efficiently without the tip seal falling or breaking.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of a scroll compressor shown as a first embodiment of the present invention.

FIG. 2 is a perspective view of a fixed scroll used in the scroll compressor.

FIG. 3 is a perspective view of an orbiting scroll used in the scroll compressor.

FIG. 4 is a cross-sectional view along a vortex of the fixed scroll or the orbiting scroll.

FIG. 5 is a view showing a process of fluid compression when the scroll compressor is driven.

FIG. 6 is a diagram showing a process of fluid compression when the scroll compressor is driven.

FIG. 7 is a view showing a process of fluid compression when the scroll compressor is driven.

FIG. 8 is a view showing a process of fluid compression when the scroll compressor is driven.

FIG. 9 is a view showing a shape in which a compression chamber of the scroll compressor is developed.

FIG. 10 is a cross-sectional view showing the overall configuration of a scroll compressor shown as a second embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the overall configuration of a scroll compressor shown as a third embodiment of the present invention.

FIG. 12 is a perspective view of a fixed scroll and an orbiting scroll used in a conventional scroll compressor.

FIG. 13 is a view showing a compression chamber at the time of a maximum capacity in a conventional scroll compressor.

FIG. 14 is a cross-sectional view showing a sliding state of a tip seal in the vicinity of a step portion of a conventional scroll compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Fixed scroll 12a End plate 12b Wall 13 Orbiting scroll 13 'Orbiting scroll 13a End plate 13a' End plate 13b Wall 31 Fixed scroll 32 Orbiting scroll 42 Step section 43 Step section 46 Bearing member HR High pressure chamber (back pressure chamber)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Susumu Matsuda 1F, Takamichi, Iwasuka-cho, Nakamura-ku, Nagoya-shi, Aichi F-term in Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. 3H039 AA03 AA04 AA12 BB15 BB25 BB28 CC02 CC03 CC04 CC05 CC06 CC07 CC21 CC24 CC25

Claims (5)

[Claims] 1. A fixed scroll having a spiral wall provided upright on one side of an end plate, and a spiral wall provided upright on one side of an end plate. And a revolving scroll supported so as to be able to revolve orbit while being prevented from rotating by rotating the end plate of the end plate of at least one of the fixed scroll and the revolving scroll. A pressure chamber is formed, and the fluid compressed by the both scrolls is introduced into the back pressure chamber so that the one scroll is pressed against the other scroll side. At least one of the scroll end plates is formed on the one side surface so that the height thereof is high at the center portion side and low at the outer end side along the vortex of the wall. The stepped portion is provided, the upper edge of the wall of the other scroll of the fixed scroll and the orbiting scroll corresponds to the step of the end plate,
A scroll compressor having a stepped shape which is divided into a plurality of parts and the height of the parts is lower at the center of the vortex and higher at the outer end. 2. The scroll compressor according to claim 1, further comprising an elastic body that presses at least one of the fixed scroll and the orbiting scroll against the other scroll. . 3. The scroll compressor according to claim 1, wherein the back pressure chamber is formed on the other side of the fixed scroll. 4. The scroll compressor according to claim 1, wherein the back pressure chamber is formed on the other side of the orbiting scroll. 5. The scroll compressor according to claim 4, further comprising: a bearing member that is engaged with the other side of the end plate of the orbiting scroll so as to revolve and revolve, and the back pressure chamber is configured to perform the orbit. A scroll compressor formed between a scroll and the bearing member.